Introducing Fractions: Summary: Introducing Fractions
This clip provides a summary of Introducing Fractions. It discusses how and why fractions are used, including for purposes of comparing one quantity with another, as a means by which to express division, and as a way to measure.
Renaming Fractions: Multiplying Through
This clip explains that one way to rename a fraction is to multiply both numerator and denominator by the same non-zero number. This is called multiplying through by the number.
Renaming Fractions: Classes of Fractions
This clip explains that all fractions can be organized into families or classes. For example, the clip continues, 1/2, 2/4, 3/6, 4/8 and 5/10 and so on all belong to the same class. Another example is any fraction whose numerator and denominator are...
Compound Denominate Numbers: Compound Units
This clip presents several practical problems involving compound units. The problems include calculating a car's speed in miles per minute; the number of gallons of gas used; the force per square foot exerted by a waterbed; and the speed of sound ex...
Compound Denominate Numbers: Practical Problems: Multiplying Compound Denominate Numbers
This clip includes practical problems that are solved by multiplying compound denominate numbers. The first of these involves figuring out the area of a rug, followed by a problem about the square footage of an office and the amount of rent due each...
Dividing Decimal Fractions: Changing the Decimal Divisor to a Whole Number
This clip states that "mathematicians never divide by decimals. If the divisor is a decimal, they change it to a whole number." The clip then explains how this is done, with the divisor multiplied by some power of ten to become a whole number and th...
Compound Denominate Numbers: Multiplying Compound Denominate Numbers
This clip explains how to multiply compound denominate numbers. The clip points out that, "
in multiplication, we don't work in columns as we do in addition
and, to multiply, the units must be the same
.(so) we convert both compound denominate nu...
Dividing Fractions: To Divide Fractions: Invert and Multiply
This clip presents the dividing fractions rule of "invert and multiply," explaining that the divisor is inverted and the dividend is multiplied. "Invert means the numerator and the denominator change places," the clip states. The clip also asks and ...
Fluid Volume: Practical Problems: Converting Between Metric and U.S. Customary Systems
This clip provides practical problems that are solved by converting between metric and U.S. units. The problems include figuring out a hospital's requirements for antiseptic solution, the capacity of an automobile's gas tank, the amount of cough syr...
Fluid Volume: Practical Problems: Unit Equivalences
This clip includes several practical problems which are solved in part through the use of unit equivalences and the unit cancellation method taught in an earlier lesson.